Dr. Liu is a geriatrician and Assistant Professor of Medicine at Boston University (BU) who studies older (?65 years) hemodialysis (HD) patients, the biggest and fastest-growing segment of the HD population. Her long-term goal is to be an independent clinician investigator developing interventions to improve mobility in older HD patients. Mobility, the ability to move reliably and safely, signifies independence and is integral to self-worth. Almost 70% of HD patients have difficulty walking. HD patients with poor mobility are twice as likely to die or be hospitalized. Most importantly, poor mobility is cited by patients as a major contributor to poor quality of life. While risk factors for poor mobility has been studied in other older populations, such insights may not be applicable to older HD patients. Older HD patients have unique challenges, like frequent travel for HD treatment and routine post-HD fatigue,that make usual mobility treatments, such as supervised exercise, extremely difficult. To successfully address poor mobility in older HD patients, a treatment approach fitting their specific needs is required. The World Health Organization states that personal, environmental, and health factors impact mobility. But aside from physiologic health factors, there has not been a systematic investigation of what factors impact mobility in older HD patients. Caregiver support likely affects mobility. The home environment has a role. Cognition is very relevant; anxiety, depression, and self-efficacy likely also impact mobility. The knowledge gap about the potentially modifiable risk factors for poor mobility in older HD patients is impeding efforts to improve mobility and thus quality of life for this highly vulnerable population. Dr. Liu will investigate the relationship of caregiver support, the home environment, cognition, anxiety, depression, and self-efficacy with mobility in older HD patients, using a sequential mixed methods approach. First, in Aim 1, she will perform key informant interviews with 40 older HD patients and 28 of their caregivers in their homes to determine how caregiver support and the home environment influences mobility. Then she will recruit a cohort of 86 older HD patients to perform in-home assessments of 1) cognition, 2) anxiety, depression, and self-efficacy, and 3) mobility. In Aim 2, the cohort data will be used to determine how cognition affects mobility in older HD patients. In Aim 3, the cohort data will be used to determine how anxiety, depression, and self-efficacy impact mobility in older HD patients. After determining the most relevant factors associated with mobility, Dr. Liu will develop a multi-factorial intervention to improve mobility in older HD patients that she will test in an R-series application. This research is at the intersection of nephrology, geriatrics, and rehabilitation; Dr. Liu is one of only a few clinician investigators focusing in this area. Led by her Primary Co-mentors, Drs. Daniel Weiner and Jonathan Bean, Dr. Liu?s outstanding mentoring team is multi-disciplinary and cross-institutional, emblematic of the collaborative BU training environment. The proposed research and training will furnish Dr. Liu with the needed experience and skills to achieve independence as a clinician investigator dedicated to improving the mobility of older HD patients.